FIG. 8.

Reduction in vasa nervorum in Per2 mutant mice. Wild-type or Per2 mutant mice were injected with rhodamine-conjugated BS-1 isolectin 0.1 mg/mouse before kill, and the sciatic nerve was harvested, paraffin embedded, and cut transversally. A: Representative photomicrographs show that the network of vasa nervorum was markedly reduced in Per2 mutant mice compared with wild-type controls. Ten sections per animal were counted using ImageJ software, and the number of vessels per square millimeter of sciatic nerve was determined. B: A significant reduction in neural vascularity in Per2 mutant mice was found compared with wild-type controls. n = 6 for wild type; n = 7 for Per2 mutant.